BENEFIT PLANS - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Interest cost	$ 9,227	$ 9,248	$ 11,786
Expected return on plan assets, net	(2,685)	(987)	(4,905)
Curtailment loss	0	0	3,137
Settlement loss (income) (reclassified from accumulated other comprehensive loss)	1,643	1,268	1,845
Non-operating pension costs	8,274	9,529	11,863
Settlement loss related to pension plan	1,732	$ 1,268	$ 1,845
Amortization of Actuarial Gains (Losses) and Settlement Gains (Losses)	$ (89)